Environmental assessment of radioactivity levels and radiation hazards in soil at North Western-Mediterranean Sea coast, Egypt

The present work aims to obtain adequate knowledge about the natural radioactivity levels and the related radiation hazard at the northwestern coastal zone of Egypt as part of the Egyptian regulations and nuclear law. Thirty-eight soil samples of different geologic formations were collected and analyzed using gamma spectrometer equipped with hyper-pure germanium (HPGe) detector. The mean activity concentrations of ²³⁸U, ²²⁶Ra, ²³²Th and ⁴⁰K in all soil samples are 29.40, 25.18, 11.22 and 159.16 Bq kg⁻¹, respectively. Those activity concentrations are below the soil world average. The activity concentrations of ²³⁸U are found to be higher than that of ²²⁶Ra and ²³²Th. The spatial patterns of the activity concentrations of these radionuclides were also presented using the geographical information system (GIS). Radiation hazard indices were assessed through the calculation of radium equivalent activity (Ra_eq) Bq kg⁻¹, external and internal hazards (H_ex, H_in), absorbed dose rate (ADR) nGy h⁻¹ and annual effective dose (AED) mSv year⁻¹. The average values of ADR and AED are 25.41 nGy h⁻¹ and 20 μSv year⁻¹, respectively. These values are below the soil world average of 59 nGy h⁻¹ and the effective dose limit of the public radiation exposure of 1 mSv year⁻¹.